1. Field of the Invention
The present invention relates to a coupling device suitable for transferring various kinds of solution such as corrosive and high purity chemical ones and ultra-pure water from the transportation tank to the storage tank and vice versa.
2. Description of the Prior Art
Japanese Patent Disclosure Sho 63-91188, for example, discloses a coupling device of this type wherein those portions of male and female pipes which are to be connected together are washed and cleaned and then connected to each other.
According to this coupling device, the front end of the male pipe is inserted into a cleaning chamber and then into a spray ring hung in the cleaning chamber and it is fixed adjacent to the front end of the female pipe fixed in the cleaning chamber and held in the spray ring. While keeping these front ends of the male and female pipes under this state, cleaning liquid is jetted against them through apertures in the inner circumference of the spray ring to wash off impurities such as dust and particles from them. An air cylinder is then driven to connect the male and female pipes together.
In the case of this coupling device, however, cleaning liquid is jetted only to outer circumferences of those front ends of the male and female pipes which are connected to each other. This makes it difficult to remove impurities from that front end face of the male pipe which is to be contacted with the front end face of the female pipe. When the male and female pipes are connected together while leaving the front end face of the male pipe under this state, therefore, impurities such as dust and particles left are mixed with a solution supplied through the pipes to thereby degrade the purity of the solution. Particularly in the case of chemical solutions whose purity must be kept high, their qualities are remarkably degraded while being supplied through the pipes. The coupling device is not suitable for high purity chemical solutions, accordingly. It is therefore used only in a limited field.